Least reflective coating made with nanorods

Change a substance’s refractive index and you can cut the amount of light it reflects. Now physicists have made a coating with the lowest index ever reported.

Fred Schubert of Rensselaer Polytechnic Institute in Troy, New York, and colleagues made films of silicon and titanium dioxide nanorods, which they then deposited onto a surface at an angle of 45 degrees. The coating is full of empty spaces, giving it a refractive index just 5 per cent more than that of air. Adding further layers cuts reflections still more (Nature Photonics …